<![CDATA[The development of biodegradable active packaging from renewable biopolymers offers an alternative to conventional plastics. This study descriptively compared gelatin–alginate films formulated with different glycerol concentrations and cinnamon essential oil (CEO)–Tween 80 emulsions. One-way ANOVA assessed overall differences among formulations. Films were prepared by solution casting with glycerol at 1, 2, and 3% (w/v) and CEO at 0.3, 0.5, and 0.7% (v/v). Film thickness, tensile strength, elongation at break, swelling degree, and antibacterial activity against Staphylococcus aureus ATCC 25923 were evaluated. Higher glycerol concentrations generally increased flexibility but reduced tensile strength. The CEO–Tween 80 emulsion affected mechanical properties and water uptake depending on formulation. Based on a composite weighted effectiveness index, G1C1 (1% glycerol, 0.3% CEO) ranked highest, driven by its maximum tensile-strength subscore. G1C1 showed a tensile strength of 15.97 MPa, elongation at break of 130.67%, and swelling degree of 528.30%. Its mean inhibition zone against S. aureus was 12.07 ± 0.42 mm (mean ± standard deviation, n = 2 independent plates). Each plate value represented the mean of two perpendicular diameter measurements. These findings suggest that gelatin–alginate films containing low CEO concentrations may be promising biodegradable functional packaging materials, although further evaluation is needed before application in active food packaging.]]>
